In what scenarios would it be advisable to use concatenation instead of interpolation in PHP?

Concatenation is advisable over interpolation in PHP when dealing with complex strings that contain special characters or when needing to concatenate multiple variables or expressions within a single string. This can help avoid parsing errors or unexpected behavior that may occur with interpolation. Additionally, concatenation can be more readable and easier to maintain in certain situations.

// Example of using concatenation instead of interpolation
$name = "John";
$age = 30;

// Using concatenation
$message = "Hello, " . $name . "! You are " . $age . " years old.";

echo $message;